A study of the plasticity in the vortex matter across the second magnetization peak in a YBCO crystal via measurements of minor hysteresis loops

Abstract

Results of an investigation of the path dependence of the critical current density J_c due to the plastic deformation of the flux line lattice in a weakly pinned YBa₂Cu₃O_7−δ (YBCO) crystal for H||c are reported. The procedure of minor hysteresis loops has been used to explore the path dependence of J_c and the metastability effects. Contrary to the behavior observed in low T_c systems. in YBCO it is found that at low temperatures, the multivaluedness in J_c(H) could persist beyond the notional peak field H_p, at which the anomalous variation in J_c(H) reaches its maximum value.